JP-A-10-215492, JP-A-2001-051716, JP-A-2002-318702 and JP-A-2004-054803 are cited as technical documents related to the field device and the system in which a plurality of the field devices is connected to each other via a network.
FIG. 14 is a configuration block diagram showing one example of the system in which a plurality of the field devices of the related art such as a sensor, an actuator, a controller, a communication measuring instrument, a measuring instrument, a recording device and a server, is connected to each other via a network. In FIG. 14, reference numeral 1 is a higher server; reference numerals 2, 3, 4, and 5 are controllers; and reference numeral 6 is a sensor group formed of a plurality of sensors.
In FIG. 14, a plurality of sensors shown as “SN01” is connected to the controller 2 via a network (not shown), and a plurality of sensors shown as “SN02” is connected to the controller 3 via the network (not shown).
In the same manner, in FIG. 14, a plurality of sensors shown as “SN03” is connected to the controller 4 via the network (not shown), and a plurality of sensors shown as “SN04” is connected to the controller 5 via the network (not shown).
The controllers 2, 3, 4, and 5 are connected to the higher server 1 via the network (not shown).
Here, an operation of the related art example shown in FIG. 14 will be briefly described herein. An operation of the sensor group 6 is controlled by the controllers 2, 3, 4, and 5 respectively, and the controllers 2, 3, 4, and 5 are centrally managed by the server 1, thereby forming a system in total, for example, a manufacturing system and the like.
In the system shown in FIG. 14, in a case of adding a function for solving a user's new request, task, etc., (hereinafter, referred to as an ‘additional task’) to a function currently running in the field device such as the controller or the server (hereinafter, described as a ‘main task’), the additional task may be executed in the same execution environment as that of the main task by adding a program or a parameter, etc., to the field device such as the controller or the server.
FIG. 15 is an explanatory diagram showing a relation between the main task operated in a field device (specifically, an application program), and an execution environment for executing the main task such as an OS (Operating System) or hardware resources such as a communication function, I/O, and the like. The main task, the execution environment, and the hardware resources are unique functions of the field device and hereinafter, these functions are described as a ‘device-unique function’ if necessary. “HW11” in FIG. 15 is hardware resources; “OS11” in FIG. 15 is an execution environment; “MA11” in FIG. 15 is a main task; and “AA11”, “AA12” and “AA13” in FIG. 15 are additional tasks (specifically, the application program).
For example, in a case of adding a group of a plurality of additional tasks (specifically, “AA11”, “AA12”, and “AA13”) as shown as “AA01” in FIG. 14 to the server 1 and the controllers 2 and 3, each additional task shown as “AA11”, “AA12”, and “AA13” in FIG. 15 is incorporated into the main task shown as “MA11” in FIG. 15
By such configuration, the additional task shown as “AA11”, “AA12”, and “AA13” in FIG. 15 can be added to the field device to be executed. Particularly, in the example of the related art example shown in FIG. 14, the additional task can be executed in the same execution environment as that of the main task by using the device-unique function (main task, execution environment, and hardware resources).
FIG. 16 is a configuration block diagram showing another example of the system of the related art in which a plurality of the field devices is connected to each other via a network. In FIG. 16, reference numeral 7 is a higher server; reference numerals 8, 9, 10, and 11 are controllers; reference numeral 12 is a sensor group formed of a plurality of sensors; and reference numerals 13, 14, and 15 are application servers.
A plurality of sensors shown as “SN21” in FIG. 16 is connected to the controller 8 via a network (not shown), and a plurality of sensors shown as “SN22” in FIG. 16 is connected to the controller 9 via the network (not shown).
In the same manner, a plurality of sensors shown as “SN23” in FIG. 16 is connected to the controller 10 via the network (not shown), and a plurality of sensors shown as “SN24” in FIG. 16 is connected to the controller 11 via the network (not shown).
The controllers 8, 9, 10, and 11 are connected to the higher server 7 via the network (not shown). The application servers 13, 14, and 15 are connected to the respective field devices via the network (not shown).
Here, an operation of the related art example shown in FIG. 16 will be briefly described herein. An operation of the sensor group 12 is controlled by the controllers 8, 9, 10, and 11, and the controllers 8, 9, 10, and 11 are centrally managed by the server 7, thereby forming a system in total, for example, a manufacturing system and the like.
In the system shown in FIG. 16, in a case of adding the additional task to a main task currently running in the field device such as the controller or the server, the field device such as the controller or the server accesses to the application servers 13, 14, and 15 to receive required services of the additional task.
FIG. 17 is an explanatory diagram showing a relation between a main task operated in a field device, and an execution environment for executing the main task or hardware resources.
“AS31” in FIG. 17 is an application server providing services of the additional task, and “FD31” in FIG. 17 is a field device in which only the main task which receives the services of the additional task is operated.
“HW31” and “HW32” in FIG. 17 are hardware resources of the application server and the field device (specifically, communication means such as a network card); “OS31” and “OS32” in FIG. 17 are execution environments of the application server and the field device (specifically, a communication control function of an OS, and the like); “MA31” in FIG.17 is the main task of the field device; and “AA31” in FIG. 17 is the additional task operated in the application server.
For example, in a case of adding the additional task provided by the application server 13 to the plurality of sensors shown as “SN21” in FIG. 16, adding the additional task provided by the application server 14 to the server 7 and the controllers 8 and 9, and adding the additional task provided by the application server 15 to the plurality of sensors shown as “SN24” in FIG. 16 and the controller 11, each field device accesses to the corresponding application server via a network (not shown) to receive the services of the additional task.
Specifically, the field device shown as “FD31” in FIG. 17 uses the additional task shown as “AA31” in FIG. 17 operated on the device-unique function (“OS32” and “HW32” in FIG. 17) of the application server shown as “AS31” in FIG. 17 by performing communication shown as “CM31” in FIG. 17 by using the device-unique function (“OS31” and “HW31” in FIG. 17) of the field device.
By such configuration, the additional task shown as “AA31” in FIG. 17 can be added to the field device and executed. Particularly, in the related art example shown in FIG. 16, there is no limitation on an adding condition of the additional task, and it is possible to add the additional task without being influenced by the resource of the field device to which the additional task is added.